Herbal Therapies and Diabetes Among Navajo Indians

In the treatment of chronic diseases like diabetes, many Native Americans value their ability to integrate traditional and western medicine (1). However, there are limited data from clinical trials about the efficacy of herbs, and health care professionals have been concerned that herbal treatments might be harmful or lead patients away from evidence-based therapies and self-monitoring of blood glucose (2).

Traditional medicines, including herbal therapies, are commonly used among the Navajo Indians (3). During a randomized clinical trial on the Navajo Nation, 203 participants recruited between 2001 and 2003 were asked about their use of traditional medicines for diabetes and their blood glucose–monitoring practices. Their most recent A1c values were abstracted from the medical record. The study, Effects of Navajo Interpreters on Diabetes Outcomes, was overseen by the Navajo Nation and the University of New Mexico institutional review boards.

Of the 203 participants, 195 (96%) responded to the question about herb use. Fifty-eight of the 195 (30%) reported that they used herbs, and some reported use of multiple herbs. Participants described the herbs in the Navajo language according to their own tradition, not according to the species or the common English name, and a Navajo-language expert with an understanding of traditional medicine reviewed and categorized the herbs. The participants identified 27 different plants. Sage was the herb most frequently mentioned (15%), with the frequency for cedar/juniper at 10%.

A total of 19% of the participants used insulin to control their diabetes (21% of the herb users, 19% of nonusers). The mean A1c value was 8.40% in the group using herbs compared with 8.35% in those not using herbs (NS). There were no significant differences in performance (P = 0.88) or frequency (P = 0.44) of self-monitoring of blood glucose. There was no significant association between herb use and sex (P = 0.72), age (P = 11), level of education (P = 0.92), ability to speak or understand English (P = 0.15 and P = 0.12, respectively), duration of diabetes (P = 0.17), or insulin use (P = 0.84). The amount of time to get to the clinic was associated with the use of herbs (P = 0.02). Those traveling ≥60 min for health care were more likely to use herbs than those traveling ≤30 min (22 and 41%, respectively).

Our findings support the observations of Kim and Kwok (3), who found that alternative medicine is widely used by different cultural groups for common diseases. Although our sample may not have been representative of all Navajos with diabetes, it is important that the use of traditional herbs in this group of patients was not associated with any measurable adverse interaction with diabetes control as measured by A1c and self-monitoring practices.